Exemplary embodiments of the present disclosure are directed to a fan blade for a gas turbine engine and apparatus and methods for non-destructive detection of electrical isolation of the fan blade.
A gas turbine fan blade may be made out of aluminum, and to protect the leading edge from erosion, a titanium sheath is attached. Titanium and aluminum are galvanically incompatible materials, so they are isolated from each other as best possible, using non-conductive materials. However and in the event the isolation between them is defeated, galvanic corrosion could occur to the blade. In particular and in an aluminum/titanium coupling, with aluminum being the less noble element, the blade would become the anode in the galvanic couple and accordingly, corrosion may occur on the aluminum blade.
Accordingly, it is desirable to provide an apparatus and method for non-destructive detection of electrical isolation in the fan blade.